1. Field of Invention
The present invention relates to a light source module and a display apparatus. More particularly, the present invention relates to a flat fluorescent lamp (FFL) with high luminous efficiency and a liquid crystal display (LCD) using the same.
2. Description of Related Art
Along with the progress in modern video technology, LCDs have been greatly used in display screens of consumable electronic products such as mobile phones, notebooks, personal computers and personal digital assistants (PDAs). However, as the liquid crystal panel of an LCD itself cannot emit light, a backlight module disposed under the liquid crystal panel is required to provide the display light source desired by the liquid crystal panel. Recently, the backlight modules on the market are mainly FFLs, cold cathode fluorescent lamps (CCFLs) and light emitting diodes (LEDs), wherein the FFLs are widely used in LCDs due to the advantages of being low in cost, taking up a small space and so on.
FIG. 1 is a partial sectional view of a conventional FFL, and FIG. 2 is a top view of the FFL. In order to make the figure clear, a part of the means in FIG. 1 is not shown in FIG. 2. Referring to FIG. 1 and FIG. 2, a conventional FFL 100 forms a plurality of discharge spaces 132 between an upper substrate 120 and a lower substrate 110 via spacers 130, wherein a discharge gas 140 is filled into the discharge spaces 132. Moreover, an electrode set 150 is disposed on the lower substrate 110 in each of the discharge spaces 132. The electrode set 150 comprises a first strip electrode 152 and a second strip electrode 154 (the electrodes 152, 154 are either anode or cathode). A dielectric layer 160 lies on the electrode set 150 to protect the electrode set 150. Moreover, a fluorescent material 170 is coated on the outer walls of the upper substrate 120 and the dielectric layer 160.
When a driving voltage is applied to the electrode set 150, an electric field is formed between the first strip electrode 152 and the second strip electrode 154, for dissociating the discharge gas 140 into plasma. Then, the electrons in an excited state in each ion in the plasma may emit UV light when returning to a ground state, and when the UV light emitted by the plasma irradiates the fluorescent material 170, the fluorescent material 170 is excited to emit light.
It should be noted that conventionally to enhance the effect of the electric field to the discharge gas 140, a plurality of electrode branches 152a is generally formed on both sides of the first strip electrode 152, so as to form a main triangular discharge area 156 with the opposite second strip electrode 154 via the point discharge of the electrode branches 152a. However, in practice, the brightness of the discharge area 156 is usually quite different from that of other areas except the discharge area 156, thus affecting the uniformity of the whole surface light source. According to the practical situation, when the brightness of the top ends of the electrode branches 152a reaches 10000 nit, the brightness of other areas only reaches 6000 nit, and when the brightness of the top ends of the electrode branches 152a reaches 7000 nit, the brightness of other areas only reaches 4000 nit.